1. Field of the Invention
The present invention relates to an optical disk apparatus for optically recording signals to an information carrier and reproducing the recorded signals by using light beams from light sources, such as lasers.
2. Related Art of the Invention
Optical disk apparatuses for playing back CD audio and CD-ROM usually use a laser light source with a wavelength of 780 nm.
However, a laser light source with a wavelength of 650 nm is used for high-density optical discs (disks having higher density and larger capacity than CD, and simply referred to as SD).
An apparatus has been proposed, which is provided with a laser with a longer wavelength of 780 nm for CD, and a laser with a shorter wavelength of 650 nm for high-density disks, whereby the laser with the longer wavelength of 780 nm is used to play back CD and CD-R, and the laser with the shorter wavelength of 650 nm is used to play back the high-density disk, SD.